Surgery is an art in which the final result has been based on a series of calculated steps. Initially, the proper diagnosis and pre-operative considerations must be confirmed. Among a multitude of important considerations are the choice of procedure, post-operative conditions and possible complications. All variables must be weighed for and against the risk to the patient and the favorable prognosis given the surgery planned. Intra-operative considerations are often times routine and may be made so by appropriate pre-operative preparation and intra-operative skill of the surgeon and surgical team. To a great measure, the surgeon's success is dependent on the ability to accurately visualize the surgical site. Knowledge of anatomy, choice of surgical approach, or location of incision, and dissection are key to this visualization.
Medical and surgical advances have greatly increased the surgeon's ability to address pathologies of the body that were once beyond a reasonable approach. For example, the reattachment of a limb would be impossible were it not for micro-surgical technique and visualization. Additionally, procedures once reserved for “open” surgical approaches have now been replaced by minimal incision approaches. In fact, minimal incision procedures are fast becoming the standard surgery of choice for many procedures. Advances in surgical-scopy technique, or surgical scope procedures, and instrumentation have drastically changed surgical approach, procedure and recovery. With these new procedures, i.e., endoscopy, arthroscopy, bronchoscopy, proctoscopy, etc., came the demand for new instrumentation appropriate for the procedure. One category of instruments is surgical retractors designed for the minimal approach usually required of surgical scope procedures and other minimal incision surgeries.
Those of ordinary skill in the art are familiar with the array of retractors used in their specialty. Many of these retractors are for highly specialized purposes and carry an eponym associated with its originator(s). For example, Senn, Seeburger, Holheimer, Weitlaner, Army-Navy and Hohmann are names associated with specific retractor types. These retractors, and countless others, have traditionally been used in what is referred to as “open surgery.” Minimal incision surgery and surgical scope procedures in joints and body cavities require different types of retraction developed specifically for the procedure contemplated. Certain of those types of retractors exist. Examples of such retractors may be found in U.S. Pat. Nos. 5,558,665 and 5,888,196.
Body cavities, such as in the gastrointestinal tract, the stomach or the rectum, have been approached in an open surgical manner with a trans-abdominal incision for the stomach and a trans-perineum incision for the rectum. The anatomy of each area carries with it attendant complications in exposure and surgical time. A third technique, or category of techniques, in approaching an area of the GI tract is laparoscopy that use cameras and instruments introduced through small incisions. This technique can approach the gastrointestinal tract from the serosal rather than the luminal side of the hollow viscus. However, exposure here can be problematic as the entry into the hollow viscus would be through an enterotomy.
Surgery in each of these areas, and using any one of these or a number of other techniques, requires multiple layer dissection and retraction of vital structures. Some of the surgical approaches to different cavities carry problems common to each approach, including problems associated with minimal approaches used for surgical scope procedures. Endoscopic approaches for the rectum, such as a proctoscope, or for the stomach, such as a gastroscope, have common problems with exposure due to the anatomy and concomitant physiology of the area. Essentially, the incision for a surgical scope procedure is usually quite small in relation to the surgical field. To provide for adequate surgical working space and procedures, techniques have been developed to allow adequate exposure in the surgical field and, for the most part, minimize trauma and surgical time in the area. In one technique, the technique of insufflation, air is forced into the chosen body cavity, the peritoneum or bladder, for example, and can facilitate exposure and visualization. Alternatively, saline streams may be introduced into a body cavity to affect enhanced visualization.
The techniques of insufflation and hydrostatic pressure, although useful, are problematic in a number of ways. First, insufflation must be continuous. The problem is maintaining the balance of exposure versus continuous air pressure, which is necessary for insufflation. Continuous insufflation can produce new problems such as respiratory compromise and air leakage into surrounding tissues. Further, weaknesses in the walls of the surgical area may be further compromised by air or water pressure to the point of tearing, leading to increased bleeding, possibility of infection and prolonged healing time. Moreover, insufflation of air into the stomach or rectum can cause bowel dilatation in other parts of the gut, which is typically undesirable. The invention disclosed herein addresses certain of these problems in exposure during GI, alimentary, retroperitoneal, thoracic and other surgeries.